In the field of a military training program an infrared firing is usually exercised in which targets are used that must radiate a heat with a temperature of at least one degree Celsius higher than the temperature of the surrounding atmosphere. It otherwise will not be possible to recognize these targets with a night-sight view finder as thereby used by the gunners. This elevated temperature of such targets provides a thermal dummy or pseudo target for example of a tank which for which infrared firing exercises then requires the use of targets having the size of about 1.80 m.times.2.30 m in accordance with the relevant NATO regulations.
For allowing a plurality of shots the targets must of course maintain their elevated temperature over an extended time period starting with the primary heating of each target and its positioning into the firing direction. This positioning is usually done by means either of a stationary swinging mechanism that comprises a clamping device having two mutually adjustable clamping jaws for interchangeably holding the targets one at a time. With this swinging mechanism the targets are brought from a horizontal rest position into an upright position in which their heat radiation may be viewed by the gunners. An alternate positioning is carried out by means of carriages on which the targets are interchangeably held already in an upright position by means of a similar clamping device. The carriages are moved relative to the firing direction.
A prior art target of the kind as herein referred is described in German OS No. 32 05 599. A heat radiation suitable for infrared firing exercises is described as being obtainable by means of a carbon or graphite felt which is arranged on a presswood board for being heated by a current that is supplied to the felt at two opposite edge portions from either two serially connected 12 Volt batteries or from a 220 Volt line current source. These targets so far have only been used for observation and not for firing exercises because they could not fulfil the respective military requirements for the larger dimensioned thermal dummy or pseudo targets of tanks calling for a relatively short upheating period, the maintenance of a uniform and almost constant heat radiation over an extended time period for allowng a plurality of shots against such targets before their interchange, and also mainly calling for an easy handling of such targets in terms of their weight and their positioning in the firing direction of the gunners.
A further prior art target system of the kind herein referred is described in German Pat. No. 30 06 462. A heat radiation usable for infrared firing exercises is described as being obtainable by means of a flexible material composed of an aluminum foil as a heat absorbing layer, a plastic foil as a protective layer allowing the passage of the heating beams of a radiation apparatus, and of a coarse-meshed net which as an intermediate layer provides heat absorbing air chambers. This multi-layered material is fixed on a wooden frame for being heated by means of a radiation apparatus that is arranged in front of the assembly for a heating primarily of the aluminum foil. Although such targets are provided with an improved heat storage capacity maintainable over an extended period of time these targets as well have so far only seldomly been used for military training programs more or less for the same reasons as mentioned before.
This invention deals with the object of providing a target system for use in infrared firing exercises in which a thermal dummy or pseudo target is obtained by means of an electrical heating device in the form of an electrical conductive resistance material which when being heated with an improved power efficiency will perform a uniform heat radiation over an extended time period to thereby allow a multiple firing against such targets which for their heating to a temperature higher than the surrounding atmosphere shall also allow an easier and at the same time more safe-proof handling under consideration of their interchange on a clamping device of the target system.
This object of the present invention is accomplished by providing a target system that principally comprises a plurality of targets each of a wooden carrier material formed as a plate of a uniform thickness which is covered with a relatively thin metallic layer in the form of a sheet made of an aluminum alloy as laminated onto this wooden plate. Each of such targets is provided for being interchangeably held by a clamping device which is formed with two mutually adjustable clamping jaws of which at least one is provided with electrically conductive heating rails for supplying a heating current to the metallic layer of the target for its electrical heating by means of a heating circuit which comprises a current source and a transformer for downwardly transforming the voltage of the electrical current. The further main feature of the inventive target system is the provision of complementary curvatures for the surfaces of the two clamping jaws of the clamping device and the heating rails allow for larger dimensioned targets the use of a relatively thin plywood panel as a carrier material for the metallic layer used as an electric heating means.